1. Field of the Invention
This invention relates to a motorized movable fence for a table saw. More particularly, this invention relates to a fence which is moved under the direction of a computer program and which is sequentially positioned according to an optimized cutting sequence.
2. Description of the Prior Art
A number of motorized fences for a table saw have been proposed to assist the woodcutter in accurately positioning a section of sheet to be cut with relation to the saw blade. Furthermore, a number of devices have been proposed which utilize a computer to accurately position the fence to its designated location.
Jureit, U.S. Pat. No. 3,610,299 discloses an automated saw in which means are provided for automatically selecting the appropriate set of dimensions and angles to be used in accordance with a preselected sheet width. The dimensions of the work piece are entered numerically to provide accurate and repeatable cutting.
Furthermore, a number of other devices have been proposed which utilize computer controlled cutting or machining under computer control to insure accuracy and to increase productivity. Motorized controls of these devices and of table saw fences in particular, are also well known.
It is desirable in the preparation and cutting of wood sheet products that the wood sheet material be cut accurately and with as little wastage as possible. In many wood working applications, a series of sheets must be cut in an identical fashion to provide all of the construction elements necessary for the completion of the project. Heretofore, this process was accomplished by manually mapping a series of sheets with the necessary cutting patterns and rearranging the patterns to minimize the wood utilized. The sheets would then be marked and cut manually by the operator of the table saw.
The cutting operation is accomplished in a manual table saw by selecting the width of sheet to be cut and moving a fence to that predetermined distance from the saw blade. The table saw itself is generally provided with a movable fence which may be manually adjusted through sliding and clamping or by a gear drive or similar electrical mechanism. In any event, the fence must be carefully placed for accurate cutting. Similarly, the sheets must be accurately marked for the same reasons.
With the advent of inexpensive personal computer power, a number of sheet cutting optimization programs such as Cut Planner 2A by Pattern Systems International or Cut Rite Plus by Holzma US have been produced. These programs permit the input of an inventory of sheet stock and the input of the dimensions for the finished cut pieces to be utilized in a project. The computer program then arranges and rearranges the cut pieces on the existing sheet stock to maximize utility and minimize wastage. A "cutting list" is then provided to the user in order to mark his sheets according to the program. While this permits the user to minimize wastage, it does not provide or assist in the accurate cutting of the sheets according to the computer output. There remains, therefore, a need in the art for a device which combines the accuracy and repetitive capabilities of a table saw utilizing a motorized fence and the accuracy and economy of a computerized sheet cutting optimization program.